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Removal of Ni (II) from aqueous solutions by adsorption onto <i style="">Cajanus cajan L </i>Milsp seed shell activated carbonshttp://nopr.niscair.res.in/handle/123456789/13036
Title: Removal of Ni (II) from aqueous solutions by adsorption onto <i style="">Cajanus cajan L </i>Milsp seed shell activated carbons
<br/>
<br/>Authors: Thamilarasu, P; Sivakumar, P; Karunakaran, K
<br/>
<br/>Abstract: The
adsorptive removal of Ni(II) from aqueous solution using <i>Cajanus cajan L </i>Milsp
seed shells activated carbon (CCC) and polypyrrole coated <i>Cajanus cajan L </i>Milsp
seed shells activated carbon (PPy/CCC) has been carried out under various
experimental conditions. Quantity of Ni(II) uptake at
50 mg of activated carbon is 25.75 mg/g for CCC and 29.60 mg/g for PPy/CCC.
Adsorption data are modeled with Freundlich, Langmuir and Temkin adsorption
isotherms. Thermodynamics parameters, such as <img src='/image/spc_char/delta.gif' border=0>H<sup>o</sup>, <img src='/image/spc_char/delta.gif' border=0>S<sup>o</sup>,
and <img src='/image/spc_char/delta.gif' border=0>G<sup>o </sup>have been calculated and the findings indicate that the
adsorption is spontaneous and endothermic. Enthalpy change values range from
8.90 kJ/mol to 23.04 kJ/mol, and based on these values the adsorption of Ni(II)
by CCC could be a physisorption. A mechanism involving intra particle diffusion
and surface adsorption has been proposed for the adsorption of Ni(II) onto the
adsorbent. Adsorbent used in this study is also characterized by FT-IR and SEM
before and after the adsorption of metal ions.
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<br/>Page(s): 414-420Removal of arsenic ions and bacteriological contamination from aqueous solutions using chitosan nanosphereshttp://nopr.niscair.res.in/handle/123456789/13035
Title: Removal of arsenic ions and bacteriological contamination from aqueous solutions using chitosan nanospheres
<br/>
<br/>Authors: Singh, P; Bajpai, J; Bajpai, A K; Shrivastava, R B
<br/>
<br/>Abstract: This paper reports study on the
removal of As (V) by chitosan nanospheres following batch studies conducted as
a function of dosage, contact time and temperature. The kinetic investigation
of the removal process reveals that the uptake of As (V) ions by chitosan is
very rapid in the first 40 min and then an equilibrium adsorption is achieved
in next 20 min. The adsorption data has been applied to Langmuir and Freundlich
isotherm equations and various experimental parameters such as solid to liquid
ratio, <i style="">p</i>H, temperature and contact
time are varied to optimize the conditions for the removal of arsenic ions.
Antibacterial studies are also performed on native chitosan and silver
nanoparticles loaded chitosan nanospheres and dissolved oxygen is calculated in
water samples treated with chitosan and Ag-chitosan nanospheres. <i style="">Escherichia coli</i> is used to test the
bactericidal efficacy of synthesized Ag-chitosan nanospheres. These nanospheres
are found to have significantly higher antibacterial activity than the native
chitosan nanospheres.
<br/>
<br/>Page(s): 403-413Hexavalent chromium removal by gingelly oil cake carbon activated with zinc chloridehttp://nopr.niscair.res.in/handle/123456789/13034
Title: Hexavalent chromium removal by gingelly oil cake carbon activated with zinc chloride
<br/>
<br/>Authors: Nagashanmugam, K B; Srinivasan, K
<br/>
<br/>Abstract: An activated carbon has been prepared from
gingelly oil cake (GOC) by zinc chloride treatment and its Cr(VI) removal
capacity is compared with that of commercial activated carbon (CAC). The effect
of experimental parameters such as <i>p</i>H, initial concentration, contact
time and adsorbents dose for Cr(VI) removal has been studied. Langmuir,
Freundlich and Temkin models are tested to describe the equilibrium isotherms.
The maximum adsorption capacity of the adsorbents calculated from Langmuir
isotherm is found to be 62.5 mg/g and 25.13 mg/g for zinc chloride treated
gingelly oil cake carbon (ZTGOC) and CAC respectively. R<sup>2</sup> values
show that both Langmuir and Freundlich models fit well to explain the
adsorption phenomenon for ZTGOC and CAC. The kinetic data fits best to pseudo-second
order model. FT-IR analysis has been used to obtain information on the nature
of possible interaction between carbon adsorbents and metal ions. SEM images
confirm the adsorption of Cr(VI) onto these adsorbents through morphological
observations. Thermodynamic study shows the feasibility of process and
spontaneous nature of the adsorption. The carbon adsorbents have also been tested
for the removal of Cr(VI) from chrome plating wastewater and &nbsp;are found to remove Cr(VI) effectively.<i style=""></i>
<br/>
<br/>Page(s): 391-402Influence of <i>Ficus religiosa</i> leaf powder on bisorption of cobalthttp://nopr.niscair.res.in/handle/123456789/13033
Title: Influence of <i>Ficus religiosa</i> leaf powder on bisorption of cobalt
<br/>
<br/>Authors: Krishna, B; Venkateswarlu, P
<br/>
<br/>Abstract: The batch-wise biosorption of cobalt by <i style="">Ficus
religiosa</i> (peepul) leaf powder has been carried out. The optimum
biosorbent dosage is 60 g/L for an equilibrium agitation time of 90 min. Percentage
removal of cobalt is increased from 70.9 to 97.2 (0.96 to 1.45 mg/g) with
decrease in acidity in the <i style="">p</i>H range
from 2 to 7. The experimental data are well represented by Freundlich (<i style="">n</i>=0.42, <i style="">K<sub>f</sub></i>=0.83 L/g, <i style="">R<sup>2</sup></i>=0.948),
Langmuir (<i style="">R<sub>L</sub></i>=0.566, <i>q</i><sub>m</sub>=
3.60 mg/g, <i style="">R<sup>2</sup></i>=0.991),
Redlich-Peterson(<i style="">R<sup>2</sup></i>=0.98)
and Temkin (<i style="">R<sup>2</sup></i>=0.98, b<sub>T</sub>
=784.52) isotherms, indicating favourable biosorption. The biosorption of Co(II)
is described by the pseudo-second order rate equation (<i style="">K</i>=0.418 g/mg-min, <i style="">R<sup>2</sup></i>=0.99)
preferably than first order rate equation (<i style="">R<sup>2</sup></i>=0.89).
The biosorption is exothermic, irreversible and spontaneous.
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<br/>Page(s): 381-390